As an example of electrophotographic image forming apparatuses, there have been known an image forming apparatus including a main apparatus body, a photosensitive drum, a processing cartridge mountable to and removable from the main apparatus body along the axial direction of the photosensitive drum, and an LED array head for exposing the photosensitive drums. In this image forming apparatus, when the processing cartridge is mounted to or removed from the main apparatus body, it is necessary to prevent interference between the processing cartridge and the LED array head. To this end, various configurations for evacuating the LED array heads have been considered.
For example, there have been proposed an image forming apparatus including a holding member that holds LED array heads and is movable in a vertical direction, and a bracket that is disposed to be adjacent to the holding member in the axial direction of photosensitive drums and is linearly movable in a direction perpendicular to both of the axial direction of the photosensitive drums and the vertical direction. In this related-art image forming apparatus, pins protruding along the axial direction of the photosensitive drums are provided at the holding member, and guide holes having tapered portions inclined diagonally upward are formed at the bracket.
In this related-art image forming apparatus, in accordance with linear movement of the bracket, the pins of the holding member are guided along the inclination of the tapered portions of the bracket, and the holding member is moved to advance or evacuate such that the LED array heads are moved between first positions where the LED array heads are close to the photosensitive drums and second positions where the LED array heads are evacuated from the photosensitive drums.